2 * Copyright(c) 2007 - 2008 Intel Corporation. All rights reserved.
4 * This program is free software; you can redistribute it and/or modify it
5 * under the terms and conditions of the GNU General Public License,
6 * version 2, as published by the Free Software Foundation.
8 * This program is distributed in the hope it will be useful, but WITHOUT
9 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
10 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
13 * You should have received a copy of the GNU General Public License along with
14 * this program; if not, write to the Free Software Foundation, Inc.,
15 * 51 Franklin St - Fifth Floor, Boston, MA 02110-1301 USA.
17 * Maintained at www.Open-FCoE.org
23 * This block discovers all FC-4 remote ports, including FCP initiators. It
24 * also handles RSCN events and re-discovery if necessary.
30 * The disc mutex is can be locked when acquiring rport locks, but may not
31 * be held when acquiring the lport lock. Refer to fc_lport.c for more
35 #include <linux/timer.h>
36 #include <linux/err.h>
37 #include <asm/unaligned.h>
39 #include <scsi/fc/fc_gs.h>
41 #include <scsi/libfc.h>
45 #define FC_DISC_RETRY_LIMIT 3 /* max retries */
46 #define FC_DISC_RETRY_DELAY 500UL /* (msecs) delay */
48 static void fc_disc_gpn_ft_req(struct fc_disc *);
49 static void fc_disc_gpn_ft_resp(struct fc_seq *, struct fc_frame *, void *);
50 static void fc_disc_done(struct fc_disc *, enum fc_disc_event);
51 static void fc_disc_timeout(struct work_struct *);
52 static int fc_disc_single(struct fc_lport *, struct fc_disc_port *);
53 static void fc_disc_restart(struct fc_disc *);
56 * fc_disc_stop_rports() - Delete all the remote ports associated with the lport
57 * @disc: The discovery job to stop remote ports on
59 * Locking Note: This function expects that the lport mutex is locked before
62 void fc_disc_stop_rports(struct fc_disc *disc)
64 struct fc_lport *lport;
65 struct fc_rport_priv *rdata, *next;
69 mutex_lock(&disc->disc_mutex);
70 list_for_each_entry_safe(rdata, next, &disc->rports, peers)
71 lport->tt.rport_logoff(rdata);
72 mutex_unlock(&disc->disc_mutex);
76 * fc_disc_recv_rscn_req() - Handle Registered State Change Notification (RSCN)
77 * @sp: The sequence of the RSCN exchange
79 * @lport: The local port that the request will be sent on
81 * Locking Note: This function expects that the disc_mutex is locked
82 * before it is called.
84 static void fc_disc_recv_rscn_req(struct fc_seq *sp, struct fc_frame *fp,
87 struct fc_lport *lport;
88 struct fc_els_rscn *rp;
89 struct fc_els_rscn_page *pp;
90 struct fc_seq_els_data rjt_data;
93 enum fc_els_rscn_ev_qual ev_qual;
94 enum fc_els_rscn_addr_fmt fmt;
95 LIST_HEAD(disc_ports);
96 struct fc_disc_port *dp, *next;
100 FC_DISC_DBG(disc, "Received an RSCN event\n");
102 /* make sure the frame contains an RSCN message */
103 rp = fc_frame_payload_get(fp, sizeof(*rp));
106 /* make sure the page length is as expected (4 bytes) */
107 if (rp->rscn_page_len != sizeof(*pp))
109 /* get the RSCN payload length */
110 len = ntohs(rp->rscn_plen);
111 if (len < sizeof(*rp))
113 /* make sure the frame contains the expected payload */
114 rp = fc_frame_payload_get(fp, len);
117 /* payload must be a multiple of the RSCN page size */
119 if (len % sizeof(*pp))
122 for (pp = (void *)(rp + 1); len > 0; len -= sizeof(*pp), pp++) {
123 ev_qual = pp->rscn_page_flags >> ELS_RSCN_EV_QUAL_BIT;
124 ev_qual &= ELS_RSCN_EV_QUAL_MASK;
125 fmt = pp->rscn_page_flags >> ELS_RSCN_ADDR_FMT_BIT;
126 fmt &= ELS_RSCN_ADDR_FMT_MASK;
128 * if we get an address format other than port
129 * (area, domain, fabric), then do a full discovery
132 case ELS_ADDR_FMT_PORT:
133 FC_DISC_DBG(disc, "Port address format for port "
134 "(%6x)\n", ntoh24(pp->rscn_fid));
135 dp = kzalloc(sizeof(*dp), GFP_KERNEL);
141 dp->port_id = ntoh24(pp->rscn_fid);
142 list_add_tail(&dp->peers, &disc_ports);
144 case ELS_ADDR_FMT_AREA:
145 case ELS_ADDR_FMT_DOM:
146 case ELS_ADDR_FMT_FAB:
148 FC_DISC_DBG(disc, "Address format is (%d)\n", fmt);
153 lport->tt.seq_els_rsp_send(sp, ELS_LS_ACC, NULL);
156 * If not doing a complete rediscovery, do GPN_ID on
157 * the individual ports mentioned in the list.
158 * If any of these get an error, do a full rediscovery.
159 * In any case, go through the list and free the entries.
161 list_for_each_entry_safe(dp, next, &disc_ports, peers) {
162 list_del(&dp->peers);
164 redisc = fc_disc_single(lport, dp);
168 FC_DISC_DBG(disc, "RSCN received: rediscovering\n");
169 fc_disc_restart(disc);
171 FC_DISC_DBG(disc, "RSCN received: not rediscovering. "
172 "redisc %d state %d in_prog %d\n",
173 redisc, lport->state, disc->pending);
178 FC_DISC_DBG(disc, "Received a bad RSCN frame\n");
180 rjt_data.reason = ELS_RJT_LOGIC;
181 rjt_data.explan = ELS_EXPL_NONE;
182 lport->tt.seq_els_rsp_send(sp, ELS_LS_RJT, &rjt_data);
187 * fc_disc_recv_req() - Handle incoming requests
188 * @sp: The sequence of the request exchange
189 * @fp: The request frame
190 * @lport: The local port receiving the request
192 * Locking Note: This function is called from the EM and will lock
193 * the disc_mutex before calling the handler for the
196 static void fc_disc_recv_req(struct fc_seq *sp, struct fc_frame *fp,
197 struct fc_lport *lport)
200 struct fc_disc *disc = &lport->disc;
202 op = fc_frame_payload_op(fp);
205 mutex_lock(&disc->disc_mutex);
206 fc_disc_recv_rscn_req(sp, fp, disc);
207 mutex_unlock(&disc->disc_mutex);
210 FC_DISC_DBG(disc, "Received an unsupported request, "
211 "the opcode is (%x)\n", op);
217 * fc_disc_restart() - Restart discovery
218 * @disc: The discovery object to be restarted
220 * Locking Note: This function expects that the disc mutex
223 static void fc_disc_restart(struct fc_disc *disc)
225 if (!disc->disc_callback)
228 FC_DISC_DBG(disc, "Restarting discovery\n");
235 * Advance disc_id. This is an arbitrary non-zero number that will
236 * match the value in the fc_rport_priv after discovery for all
237 * freshly-discovered remote ports. Avoid wrapping to zero.
239 disc->disc_id = (disc->disc_id + 2) | 1;
240 disc->retry_count = 0;
241 fc_disc_gpn_ft_req(disc);
245 * fc_disc_start() - Start discovery on a local port
246 * @lport: The local port to have discovery started on
247 * @disc_callback: Callback function to be called when discovery is complete
249 static void fc_disc_start(void (*disc_callback)(struct fc_lport *,
251 struct fc_lport *lport)
253 struct fc_disc *disc = &lport->disc;
256 * At this point we may have a new disc job or an existing
257 * one. Either way, let's lock when we make changes to it
258 * and send the GPN_FT request.
260 mutex_lock(&disc->disc_mutex);
261 disc->disc_callback = disc_callback;
262 fc_disc_restart(disc);
263 mutex_unlock(&disc->disc_mutex);
267 * fc_disc_done() - Discovery has been completed
268 * @disc: The discovery context
269 * @event: The discovery completion status
271 * Locking Note: This function expects that the disc mutex is locked before
272 * it is called. The discovery callback is then made with the lock released,
273 * and the lock is re-taken before returning from this function
275 static void fc_disc_done(struct fc_disc *disc, enum fc_disc_event event)
277 struct fc_lport *lport = disc->lport;
278 struct fc_rport_priv *rdata;
280 FC_DISC_DBG(disc, "Discovery complete\n");
283 if (disc->requested) {
284 fc_disc_restart(disc);
289 * Go through all remote ports. If they were found in the latest
290 * discovery, reverify or log them in. Otherwise, log them out.
291 * Skip ports which were never discovered. These are the dNS port
292 * and ports which were created by PLOGI.
294 list_for_each_entry(rdata, &disc->rports, peers) {
297 if (rdata->disc_id == disc->disc_id)
298 lport->tt.rport_login(rdata);
300 lport->tt.rport_logoff(rdata);
303 mutex_unlock(&disc->disc_mutex);
304 disc->disc_callback(lport, event);
305 mutex_lock(&disc->disc_mutex);
309 * fc_disc_error() - Handle error on dNS request
310 * @disc: The discovery context
311 * @fp: The error code encoded as a frame pointer
313 static void fc_disc_error(struct fc_disc *disc, struct fc_frame *fp)
315 struct fc_lport *lport = disc->lport;
316 unsigned long delay = 0;
318 FC_DISC_DBG(disc, "Error %ld, retries %d/%d\n",
319 PTR_ERR(fp), disc->retry_count,
320 FC_DISC_RETRY_LIMIT);
322 if (!fp || PTR_ERR(fp) == -FC_EX_TIMEOUT) {
324 * Memory allocation failure, or the exchange timed out,
327 if (disc->retry_count < FC_DISC_RETRY_LIMIT) {
328 /* go ahead and retry */
330 delay = msecs_to_jiffies(FC_DISC_RETRY_DELAY);
332 delay = msecs_to_jiffies(lport->e_d_tov);
334 /* timeout faster first time */
335 if (!disc->retry_count)
339 schedule_delayed_work(&disc->disc_work, delay);
341 fc_disc_done(disc, DISC_EV_FAILED);
346 * fc_disc_gpn_ft_req() - Send Get Port Names by FC-4 type (GPN_FT) request
347 * @lport: The discovery context
349 * Locking Note: This function expects that the disc_mutex is locked
350 * before it is called.
352 static void fc_disc_gpn_ft_req(struct fc_disc *disc)
355 struct fc_lport *lport = disc->lport;
357 WARN_ON(!fc_lport_test_ready(lport));
364 fp = fc_frame_alloc(lport,
365 sizeof(struct fc_ct_hdr) +
366 sizeof(struct fc_ns_gid_ft));
370 if (lport->tt.elsct_send(lport, 0, fp,
373 disc, 3 * lport->r_a_tov))
376 fc_disc_error(disc, NULL);
380 * fc_disc_gpn_ft_parse() - Parse the body of the dNS GPN_FT response.
381 * @lport: The local port the GPN_FT was received on
382 * @buf: The GPN_FT response buffer
383 * @len: The size of response buffer
385 * Goes through the list of IDs and names resulting from a request.
387 static int fc_disc_gpn_ft_parse(struct fc_disc *disc, void *buf, size_t len)
389 struct fc_lport *lport;
390 struct fc_gpn_ft_resp *np;
395 struct fc_rport_identifiers ids;
396 struct fc_rport_priv *rdata;
402 * Handle partial name record left over from previous call.
406 np = (struct fc_gpn_ft_resp *)bp;
407 tlen = disc->buf_len;
410 WARN_ON(tlen >= sizeof(*np));
411 plen = sizeof(*np) - tlen;
413 WARN_ON(plen >= sizeof(*np));
416 np = &disc->partial_buf;
417 memcpy((char *)np + tlen, bp, plen);
420 * Set bp so that the loop below will advance it to the
421 * first valid full name element.
426 disc->buf_len = (unsigned char) plen;
427 if (plen == sizeof(*np))
432 * Handle full name records, including the one filled from above.
433 * Normally, np == bp and plen == len, but from the partial case above,
434 * bp, len describe the overall buffer, and np, plen describe the
435 * partial buffer, which if would usually be full now.
436 * After the first time through the loop, things return to "normal".
438 while (plen >= sizeof(*np)) {
439 ids.port_id = ntoh24(np->fp_fid);
440 ids.port_name = ntohll(np->fp_wwpn);
442 if (ids.port_id != fc_host_port_id(lport->host) &&
443 ids.port_name != lport->wwpn) {
444 rdata = lport->tt.rport_create(lport, ids.port_id);
446 rdata->ids.port_name = ids.port_name;
447 rdata->disc_id = disc->disc_id;
449 printk(KERN_WARNING "libfc: Failed to allocate "
450 "memory for the newly discovered port "
451 "(%6x)\n", ids.port_id);
456 if (np->fp_flags & FC_NS_FID_LAST) {
457 fc_disc_done(disc, DISC_EV_SUCCESS);
463 np = (struct fc_gpn_ft_resp *)bp;
468 * Save any partial record at the end of the buffer for next time.
470 if (error == 0 && len > 0 && len < sizeof(*np)) {
471 if (np != &disc->partial_buf) {
472 FC_DISC_DBG(disc, "Partial buffer remains "
474 memcpy(&disc->partial_buf, np, len);
476 disc->buf_len = (unsigned char) len;
482 * fc_disc_timeout() - Handler for discovery timeouts
483 * @work: Structure holding discovery context that needs to retry discovery
485 static void fc_disc_timeout(struct work_struct *work)
487 struct fc_disc *disc = container_of(work,
490 mutex_lock(&disc->disc_mutex);
491 fc_disc_gpn_ft_req(disc);
492 mutex_unlock(&disc->disc_mutex);
496 * fc_disc_gpn_ft_resp() - Handle a response frame from Get Port Names (GPN_FT)
497 * @sp: The sequence that the GPN_FT response was received on
498 * @fp: The GPN_FT response frame
499 * @lp_arg: The discovery context
501 * Locking Note: This function is called without disc mutex held, and
502 * should do all its processing with the mutex held
504 static void fc_disc_gpn_ft_resp(struct fc_seq *sp, struct fc_frame *fp,
507 struct fc_disc *disc = disc_arg;
508 struct fc_ct_hdr *cp;
509 struct fc_frame_header *fh;
510 enum fc_disc_event event = DISC_EV_NONE;
511 unsigned int seq_cnt;
515 mutex_lock(&disc->disc_mutex);
516 FC_DISC_DBG(disc, "Received a GPN_FT response\n");
519 fc_disc_error(disc, fp);
520 mutex_unlock(&disc->disc_mutex);
524 WARN_ON(!fc_frame_is_linear(fp)); /* buffer must be contiguous */
525 fh = fc_frame_header_get(fp);
526 len = fr_len(fp) - sizeof(*fh);
527 seq_cnt = ntohs(fh->fh_seq_cnt);
528 if (fr_sof(fp) == FC_SOF_I3 && seq_cnt == 0 && disc->seq_count == 0) {
529 cp = fc_frame_payload_get(fp, sizeof(*cp));
531 FC_DISC_DBG(disc, "GPN_FT response too short, len %d\n",
533 event = DISC_EV_FAILED;
534 } else if (ntohs(cp->ct_cmd) == FC_FS_ACC) {
536 /* Accepted, parse the response. */
538 error = fc_disc_gpn_ft_parse(disc, cp + 1, len);
539 } else if (ntohs(cp->ct_cmd) == FC_FS_RJT) {
540 FC_DISC_DBG(disc, "GPN_FT rejected reason %x exp %x "
541 "(check zoning)\n", cp->ct_reason,
543 event = DISC_EV_FAILED;
544 if (cp->ct_reason == FC_FS_RJT_UNABL &&
545 cp->ct_explan == FC_FS_EXP_FTNR)
546 event = DISC_EV_SUCCESS;
548 FC_DISC_DBG(disc, "GPN_FT unexpected response code "
549 "%x\n", ntohs(cp->ct_cmd));
550 event = DISC_EV_FAILED;
552 } else if (fr_sof(fp) == FC_SOF_N3 && seq_cnt == disc->seq_count) {
553 error = fc_disc_gpn_ft_parse(disc, fh + 1, len);
555 FC_DISC_DBG(disc, "GPN_FT unexpected frame - out of sequence? "
556 "seq_cnt %x expected %x sof %x eof %x\n",
557 seq_cnt, disc->seq_count, fr_sof(fp), fr_eof(fp));
558 event = DISC_EV_FAILED;
561 fc_disc_error(disc, fp);
562 else if (event != DISC_EV_NONE)
563 fc_disc_done(disc, event);
565 mutex_unlock(&disc->disc_mutex);
569 * fc_disc_gpn_id_resp() - Handle a response frame from Get Port Names (GPN_ID)
570 * @sp: The sequence the GPN_ID is on
571 * @fp: The response frame
572 * @rdata_arg: The remote port that sent the GPN_ID response
574 * Locking Note: This function is called without disc mutex held.
576 static void fc_disc_gpn_id_resp(struct fc_seq *sp, struct fc_frame *fp,
579 struct fc_rport_priv *rdata = rdata_arg;
580 struct fc_rport_priv *new_rdata;
581 struct fc_lport *lport;
582 struct fc_disc *disc;
583 struct fc_ct_hdr *cp;
584 struct fc_ns_gid_pn *pn;
587 lport = rdata->local_port;
590 mutex_lock(&disc->disc_mutex);
591 if (PTR_ERR(fp) == -FC_EX_CLOSED)
596 cp = fc_frame_payload_get(fp, sizeof(*cp));
599 if (ntohs(cp->ct_cmd) == FC_FS_ACC) {
600 if (fr_len(fp) < sizeof(struct fc_frame_header) +
601 sizeof(*cp) + sizeof(*pn))
603 pn = (struct fc_ns_gid_pn *)(cp + 1);
604 port_name = get_unaligned_be64(&pn->fn_wwpn);
605 if (rdata->ids.port_name == -1)
606 rdata->ids.port_name = port_name;
607 else if (rdata->ids.port_name != port_name) {
608 FC_DISC_DBG(disc, "GPN_ID accepted. WWPN changed. "
609 "Port-id %x wwpn %llx\n",
610 rdata->ids.port_id, port_name);
611 lport->tt.rport_logoff(rdata);
613 new_rdata = lport->tt.rport_create(lport,
616 new_rdata->disc_id = disc->disc_id;
617 lport->tt.rport_login(new_rdata);
621 rdata->disc_id = disc->disc_id;
622 lport->tt.rport_login(rdata);
623 } else if (ntohs(cp->ct_cmd) == FC_FS_RJT) {
624 FC_DISC_DBG(disc, "GPN_ID rejected reason %x exp %x\n",
625 cp->ct_reason, cp->ct_explan);
626 lport->tt.rport_logoff(rdata);
628 FC_DISC_DBG(disc, "GPN_ID unexpected response code %x\n",
631 fc_disc_restart(disc);
634 mutex_unlock(&disc->disc_mutex);
635 kref_put(&rdata->kref, lport->tt.rport_destroy);
639 * fc_disc_gpn_id_req() - Send Get Port Names by ID (GPN_ID) request
640 * @lport: The local port to initiate discovery on
641 * @rdata: remote port private data
643 * Locking Note: This function expects that the disc_mutex is locked
644 * before it is called.
645 * On failure, an error code is returned.
647 static int fc_disc_gpn_id_req(struct fc_lport *lport,
648 struct fc_rport_priv *rdata)
652 fp = fc_frame_alloc(lport, sizeof(struct fc_ct_hdr) +
653 sizeof(struct fc_ns_fid));
656 if (!lport->tt.elsct_send(lport, rdata->ids.port_id, fp, FC_NS_GPN_ID,
657 fc_disc_gpn_id_resp, rdata,
660 kref_get(&rdata->kref);
665 * fc_disc_single() - Discover the directory information for a single target
666 * @lport: The local port the remote port is associated with
667 * @dp: The port to rediscover
669 * Locking Note: This function expects that the disc_mutex is locked
670 * before it is called.
672 static int fc_disc_single(struct fc_lport *lport, struct fc_disc_port *dp)
674 struct fc_rport_priv *rdata;
676 rdata = lport->tt.rport_create(lport, dp->port_id);
680 return fc_disc_gpn_id_req(lport, rdata);
684 * fc_disc_stop() - Stop discovery for a given lport
685 * @lport: The local port that discovery should stop on
687 void fc_disc_stop(struct fc_lport *lport)
689 struct fc_disc *disc = &lport->disc;
692 cancel_delayed_work_sync(&disc->disc_work);
693 fc_disc_stop_rports(disc);
698 * fc_disc_stop_final() - Stop discovery for a given lport
699 * @lport: The lport that discovery should stop on
701 * This function will block until discovery has been
702 * completely stopped and all rports have been deleted.
704 void fc_disc_stop_final(struct fc_lport *lport)
707 lport->tt.rport_flush_queue();
711 * fc_disc_init() - Initialize the discovery layer for a local port
712 * @lport: The local port that needs the discovery layer to be initialized
714 int fc_disc_init(struct fc_lport *lport)
716 struct fc_disc *disc;
718 if (!lport->tt.disc_start)
719 lport->tt.disc_start = fc_disc_start;
721 if (!lport->tt.disc_stop)
722 lport->tt.disc_stop = fc_disc_stop;
724 if (!lport->tt.disc_stop_final)
725 lport->tt.disc_stop_final = fc_disc_stop_final;
727 if (!lport->tt.disc_recv_req)
728 lport->tt.disc_recv_req = fc_disc_recv_req;
731 INIT_DELAYED_WORK(&disc->disc_work, fc_disc_timeout);
732 mutex_init(&disc->disc_mutex);
733 INIT_LIST_HEAD(&disc->rports);
739 EXPORT_SYMBOL(fc_disc_init);